can,t connect with arduino (no replies)

Hello guys,

i'am trying to calibrate my prusa. I have a sanguilolu 1.3a. when i want to upload the compiled file i get the following message:

avrdude: stk500_getsync(): not in sync: resp=0xed

i've tried several things already, from what i have read on the wiki and the internet

pushing the reset button when uploading
changing the bautrate
changing firmware

i'am pretty new to al of this, i really hope you guys can help me i've being trying for several hours and i can't fix the problem.